Phase change support material composition

ABSTRACT

A jettable non-curable support material composition useful for three-dimensional ink jet printing comprising at least one fatty alcohol and at least one abietic rosin ester alcohol, wherein the support material has a melting point between about 50° C. to about 65° C. and a freezing point between about 45° C. to about 55° C.

[0001] This application is a continuation-in-part application of U.S.Ser. No. 09/971,247 filed Oct. 3, 2001 and assigned to the assignee ofthe present invention.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to selected ultra-violet light (UV)curable hot melt (or phase change) compositions and non-curable supportmaterial that can be used in a solid object printer to produce strongand desirable three-dimensional parts from CAD designs. In particular,this invention relates to non-curable phase change support compositionswhich are comprised of at least one fatty alcohol and an abietic rosinester tackifier.

[0004] 2. Description of the Relevant Art

[0005] Commercially available hot melt printers such as thethree-dimensional ThermoJet solid object printer available from 3DSystems of Valencia, Calif., use a phase change material or ink that isjetted through a print head as a liquid to form wax-like thermopolymerparts. These parts contain mixtures of various waxes and polymers andare solid at ambient temperatures, but convert to a liquid phase atelevated jetting temperatures. Accordingly, phase change materials usedin such printers are required to have a melting point of at least 65° C.and a viscosity of about 13 cPs at about 130° C. to about 140° C.(jetting temperature). Suitable waxes useful in these jettable phasechange materials have included paraffin, microcrystalline waxes,polyethylene waxes, ester waxes and fatty amide waxes. Suitable polymersuseful for these phase change materials have included polyurethaneresins, tall oil rosin and rosin ester polymers.

[0006] Existing phase change materials have some problems associatedeither with their physical characteristics (e.g. they are weak andbrittle and subject to cracking after being jetted) or have processinglimitations (e.g. they must be jetted at relatively high temperatures(130-140° C.)) because of the high viscosities of the individualcomponents of such materials. Additionally there is a need for supportmaterial that is easily jetted, but is also easily and quickly removedfrom the three-dimensional part. Accordingly, there is a need for bettermaterials that overcome these problems. The present invention isbelieved to solve these problems.

[0007] This patent application is related to U.S. application Ser. No.09/924,608 filed Aug. 6, 2001, which is a continuation of prior U.S.application Ser. No. 09/252,512, filed Feb. 18,1999, now U.S. Pat. No.6,270,335, which is a divisional of U.S. application Ser. No.08/722,335, filed Sep. 27, 1996, now abandoned, which is acontinuation-in-part of U.S. application Ser. No. 08/534,813, filed Sep.27, 1995, now abandoned. This application also relates to U.S. Pat. No.6,193,923 (Ser. No. 09/252,512) which issued on Feb. 27, 2001 and is adivisional of Ser. No. 08/722,335. All of these related applications areincorporated by reference in their entirety herein.

BRIEF SUMMARY OF THE INVENTION

[0008] Therefore, one aspect of the present invention is directed to anon-curable support material composition useful for three-dimensionalink jet solid object fabrication in combination with a curable buildmaterial, the support material comprising at least one fatty alcohol andan abietic rosin ester tackifier, wherein the support material has amelting point higher than the uncured build material, but a lowermelting point than the softening point of the cured build material.

[0009] Another aspect of the present invention is directed to a methodfor creating raised and special printing effects using ink jettechnology comprising the steps of:

[0010] depositing a UV light curable composition on the area selectedfor the special printing effects in an amount corresponding to the areaselected and the height of the raised area relative to the medium onwhich it is deposited;

[0011] depositing a non-curable support material on the area selectedwherein the amount of support material to be deposited corresponds tothe area selected for said printing effects and the geometry of theraised area formed by the UV light curable composition relative to themedium on which said composition is deposited;

[0012] curing said area with UV light; and

[0013] applying heat to melt away the support material.

[0014] Still another aspect of the present invention is directed to aselective deposition modeling method of forming at least a portion of athree-dimensional object on a layer-by-layer basis, comprising the stepsof:

[0015] a) generating computer data corresponding to layers of saidobject;

[0016] b) providing a UV curable build material which is a fluid at atleast one temperature between 40° C. and about 90° C.;

[0017] c) providing a support material which is a fluid at at least onetemperature between about 40° C. and about 90° C. comprising at leastone fatty alcohol of the structure C_(n)H_(2n+1)OH wherein n is aninteger from about 12 to about 22 and an abietic rosin ester tackifier;

[0018] d) elevating the temperature of the build material and thesupport material to a temperature above about 70° C. to about 90° C.;

[0019] e) selectively dispensing the build material at the elevatedtemperature according to the computer data to form a layer of theobject;

[0020] f) selectively dispensing the support material at the elevatedtemperature according to the computer data to form a layer of supportmaterial contiguous to the build material;

[0021] g) providing an environment that lowers the temperature of saiddispensed build material and support material into a solid state;

[0022] h) subjecting the dispensed build material to a UV light to curethe build material;

[0023] i) repeating steps e), f), g) and h) to form subsequent layersuntil at least said portion of the object is formed; and

[0024] j) applying heat to melt away the support material.

[0025] The non-curable support material of the present invention has theadvantage of having a low-melting point that permits the supportmaterial to be removed from three-dimensional parts more easily bymelting at lower temperatures.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] The term “(meth)acrylate” is used herein to mean either or bothmethacrylate or acrylate.

[0027] The term “UV” or “ultra violet light” is used herein to mean anyappropriate form of actinic radiation which is useful in curing thecompositions of the present invention.

[0028] The UV curable urethane (meth)acrylate resins used herein can beany methacrylate or acrylate resin which polymerizes in the presence ofa free radical photoinitiator, is thermally stable in an exposed statefor at least one week at the jetting temperature (about 80° C.) and forat least 4 weeks in an enclosed state, and has a boiling point greaterthan the jetting temperature. It also preferably has a flash point abovethe jetting temperature, and preferably forms a tough, high moduluspolymer when aggregated with other (meth)acrylate monomers andoligomers. It is also preferably curable under UV light at wavelengthsfrom about 300 to about 400 nanometers. Alternatively, this componentalso may be curable in the visible light range (i.e. above about 400nanometers) provided appropriate operator shielding is present.

[0029] These urethane (meth)acrylates used as the aforementionedcomponent (i) are known to those skilled in the art and can be preparedin a known manner typically by reacting a hydroxyl-terminatedpolyurethane with acrylic acid or methacrylic acid to the correspondingurethane acrylate, or by reacting as isocyanate-terminated prepolymerwith hydroxyalkyl acrylates or methacrylates to the urethane acrylate.Suitable processes are disclosed, inter alia, in EP-A 114 982 and EP-A133 908. The molecular weight of such acrylates is generally in therange from 400 to 10,000, preferably from 500 to 7,000. Urethaneacrylates are also commercially available by the SARTOMER Company underthe product names CN980, CN981, CN975 and CN2901. The preferred amountof the urethane (meth)acrylate resin is from about 20% to about 40% byweight of the composition.

[0030] The waxes used herein are preferably urethane waxes and may bemono, di or higher functionality. Other waxes such as hydrocarbon waxescan instead be used. These include hydrogenated waxes, paraffin waxes,microcrystalline waxes, fatty ester waxes, and the like.

[0031] The urethane waxes used herein can either be inert urethane waxesor reactive urethane waxes that have one or more functional groupsreactive with the aforementioned (meth)acrylate compounds (i), (iii) or(iv). One preferred class of inert linear urethane waxes has thechemical formula Cl₁₈H₃₇NCOOC_(n)H_((2n+1)) wherein n is an integer from4 to 16. Another preferred class of reactive linear urethane waxes hasthe chemical formula C_(n)H_((2n+1))NC(O)OC_(m)H_((2m))OC(O)C(CH₃)═CH₂wherein n is an integer from about 12 to about 18 and m is an integerfrom about 2 to about 12. Another preferred class of reactive urethanewax has the chemical formula C_(n)H_((2n+1))O(O)CNC₂H₄OOCC(CH₃)═CH₂wherein n is an integer from about 4 to about 18. Preferably, the totalamount of urethane wax in the UV curable composition is from about 5% toabout 25% by weight. The most preferred urethane waxes are ADS038[1-dodecyl-N-octadecyl carbamate: CH₃(CH₂)₁₇NCOO(CH₂)₁₁CH₃] and ADS043[1-hexadecyl-N-octadecyl carbamate: CH₃(CH₂)₁₇NCOO(CH₂)₁₅CH₃] waxesavailable from American Dye Source, Inc. of Baie D'Urfe, Quebec, Canada.It is preferred that they be used in combination. Preferably, thefreezing point of the urethane wax is greater than about 40° C. when inthe UV curable composition. This facilitates planarization and layerheight correction of the jetted materials.

[0032] The (meth)acrylate diluent used herein can be any (meth)acrylatehaving a low viscosity, typically less than about 13 cPs. However lowerfunctionality materials are preferred, especially monofunctional(meth)acrylates, since these incur less polymerization shrinkage andtherefore reduce printed object distortion. The diluent or diluents areadded to the composition to mainly control viscosity, but also improvethe other physical properties of the composition including improvingadhesion of the cured composition to the build platform. The preferredamount of the (meth)acrylate diluent is from about 10% to about 60% byweight of the composition. For low molecular weight materials,methacrylates, dimethacrylates, triacrylates, and diacrylates can beused in a variety of combinations. These include tetrahydrofurfurylmethacrylate, triethylene glycol dimethacrylate, 2-phenoxyethylmethacrylate, lauryl methacrylate, ethoxylated trimethylolpropanetriacrylate, polypropylene glycol monomethacrylate, polyethylene glycolmonomethacrylate, cyclohexane dimethanol diacrylate, and tridecylmethacrylate.

[0033] Other compounds useful as the aforementioned component (iii)include the diacrylate and dimethacrylate esters of aliphatic,cycloaliphatic or aromatic diols, including 1,3- or 1,4-butanediol,neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol,tetraethylene glycol, polyethylene glycol, tripropylene glycol,ethoxylated or propoxylated neopentyl glycol,1,4-dihydroxymethylcyclohexane, 2,2-bis(4-hydroxycyclohexyl)propane orbis(4-hydroxycyclohexyl)methane, hydroquinone, 4,4′-dihydroxybiphenyl,bisphenol A, bisphenol F, bisphenol S, ethoxylated or propoxylatedbisphenol A, ethoxylated or propoxylated bisphenol F or ethoxylated orpropoxylated bisphenol S.

[0034] Illustrative examples of tri(meth)acrylates which may be usefulas component (iii) are: 1,1,1-trimethylolpropane triacrylate ormethacrylate, ethoxylated or propoxylated1,1,1-trimethylolpropanetriacrylate or methacrylate, ethoxylated orpropoxylated glycerol triacrylate, pentaerythritol monohydroxytriacrylate or methacrylate; and also higher functional acrylates ormethacrylates such as dipentaerythritol monohydroxy pentaacrylate orbis(trimethylolpropane) tetraacrylate. Such compounds are known to theskilled person and some are commercially available. Preferably thesecompounds useful as a diluent have a molecular weight in the range from250 to 700.

[0035] Illustrative of the diluents potentially useful in the novelcompositions of the present invention may also be selected from thefollowing compounds: allyl acrylate, allyl methacrylate, methyl(meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl(meth)acrylate, isobutyl (meth)acrylate, n-hexyl (meth)acrylate,2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl(meth)acrylate and n-dodecyl (meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2- and 3-hydroxypropyl (meth)acrylate,2-methoxyethyl(meth)acrylate, 2-ethoxyethyl (meth)acrylate and 2- or3-ethoxypropyl (meth)acrylate, tetrahydrofurfuryl methacrylate,2-(2-ethoxyethoxy)ethyl acrylate, cyclohexyl methacrylate,2-phenoxyethyl acrylate, glycidyl acrylate and isodecyl acrylate. Suchproducts are also known and some are commercially available, as from theSartomer Company, Inc.

[0036] The photoinitiator used herein is preferably an alpha-cleavagetype (unimolecular decomposition process) photoinitiator or a hydrogenabstraction photosensitizer-tertiary amine synergist, that absorbs lightpreferably between about 250 nm and about 400 nm, more preferably fromabout 300 nm to about 365 nm, to yield free radical(s). Examples ofalpha cleavage photoinitiators are Irgacure 184 (CAS 947-19-3), Irgacure369 (CAS 119313-12-1), and Irgacure 819 (CAS 162881-26-7). An example ofa photosensitizer amine combination is Darocur BP (CAS 119-61-9) withdiethylaminoethylmethacrylate. The preferred amount of photoinitiator isfrom about 0.1% to about 5% by weight of the composition. The chemicalformula of these photoinitiators is shown below:

[0037] It should be noted that any type of photoinitiator which, whenirradiated suitably, forms free radicals can be employed as theaforementioned component (iv) in the novel compositions. The particularphotoinitiator is selected based upon the type of actinic radiationemployed to initiate the polymerization. Other typical knownphotoinitiators are benzoins, including benzoin, benzoin ethers, such asbenzoin methyl ether, benzoin ethyl ether and benzoin isopropyl ether,benzoin phenyl ether and benzoin acetate, acetophenones, includingacetophenone, 2,2-dimethoxyacetophenone and 1,1-dichloroacetophenone,benzil, benzil ketals, such as benzil dimethyl ketal and benzil diethylketal, anthraquinones, including 2-methylanthraquinone,2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinoneand 2-amylanthraquinone, triphenylphosphine, benzoylphosphine oxides,for example 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin TPO),benzophenones, such as benzophenone and4,4′-bis(N,N′-dimethylamino)benzophenone, thioxanthones and xanthones,acridine derivatives, phenazine derivatives, quinoxaline derivatives or1-phenyl-1,2-propanedione, 2-O-benzoyl oxime, 1-aminophenyl ketones or1-hydroxyphenyl ketones, such as 1-hydroxycyclohexyl phenyl ketone,phenyl 1-hydroxyisopropyl ketone and 4-isopropylphenyl1-hydroxyisopropyl ketone, all of which are known compounds.

[0038] For example, suitable photoinitiators which are normally used incombination with a HeCd laser as radiation source are acetophenones,conveniently 2,2-dialkoxybenzophenones and 1-hydroxyphenyl ketones, forexample 1-hydroxycyclohexyl phenyl ketone or 2-hydroxyisopropyl phenylketone (=2-hydroxy-2,2-dimethylacetophenone).

[0039] Another class of photoinitiators which are normally employed whenirradiating with argon ion lasers are the benzil ketals, typicallybenzil dimethyl ketal. Preferably the photoinitiator is anα-hydroxyphenyl ketone, benzil dimethyl ketal or2,4,6-trimethylbenzoyldiphenylphosphine oxide or a mixture of theseinitiators.

[0040] Another class of suitable photoinitiators comprises the ionicdye-counter ion compounds which are capable of absorbing actinicradiation and generating free radicals which are able to initiate thepolymerization of the (meth)acrylates. Novel compositions containingionic dye-counter ion compounds can be cured more variably in this waywith visible light within the adjustable wavelength range of about 400nm to about 700 nm. Ionic dye-counter ion compounds and their mode ofaction are known, for example from EP-A-0 223 587 and U.S. Pat. Nos.4,751,102; 4,772,530 and 4,772,541.

[0041] The polymerization inhibitor used herein is preferablymethoxyhydroquinone (MEHQ). This component is added to give additionalthermal stability to the composition. The preferred amount ofpolymerization inhibitor is from about 0.1% to about 1% by weight of thecomposition. The polymerization inhibitor preferably is incorporatedinto the commercially provided reactive ingredients.

[0042] Optional components to the UV curable composition may include UVstabilizers, slip agents, wetting agents, flow control agents,sensitizers, antiprecipitants, surfactants, dyes, pigments or fillers.One preferred optional ingredient is an aliphatic/aromatic epoxyacrylate blend, such as Ebecryl 3200, or bis-phenol-A-di(meth)acrylate.It aids in the adhesion of the composition to the build platform, helpsto reduce shrinkage and increases the flexural modulus of the curedmaterial. It is preferably used in amounts from about 1% to about 20% byweight of the composition.

[0043] The preferred method of making the composition is to place all ofthe ingredients into a reaction vessel and then heating the mixture toabout 75° C. to about 95° C. with stirring. The heating and stirring arecontinued until the mixture attains a homogenized molten state. Themolten mixture is preferably filtered while in a flowable state toremove any large undesirable particles that may interfere with laterjetting. The filtered mixture is then cooled to ambient temperaturesuntil it is heated in the ink jet printer.

[0044] The solid photo-cured compositions of the present inventionpreferably possess the following physical characteristics:

[0045] 1. Tensile Strength of at least 2,000 psia;

[0046] 2. Tensile Modulus of at least 100,000 psia;

[0047] 3. Tensile elongation of at least 9%;

[0048] 4. Hardness of at least 60 shore D;

[0049] 5. Impact Strength of at least 0.2 ft-lb/in (Izod notched);

[0050] 6. Flexural Strength of at least 1,500 psia; and

[0051] 7. Flexural Modulus of at least 2,500 psia.

[0052] The liquid photo-curable compositions of the present inventionpreferably possess the following physical characteristics:

[0053]1. Melting point from about 45° C. to about 65° C. (MP must beless than the jetting temperature);

[0054] 2. Freezing point from about 33° C. to about 60° C.;

[0055] 3. Jetting viscosity of about 10 to about 16 cPs at 70° C.-95°C.; and

[0056] 4. Thermally stable for at least 3 days at the jettingtemperature.

[0057] The UV curable hot melt material may be used with piezoelectricink jet print heads to build digital three-dimensional objects using aUV lamp to cure the jetted material.

[0058] In one embodiment of the present invention, a preselected amountof the UV curable composition of the present invention is jetted throughthe print head or plurality of print heads of a suitable ink jet printerto form a layer onto a build support platform in a build chamber. Eachlayer of material is deposited according to the preselected CADparameters. A suitable print head to deposit the material is thepiezoelectric Z850 print head available from Xerox Corporation's OfficeProducts Business Unit in Wilsonville, Oreg.

[0059] The temperature of the build environment is controlled so thatthe jetted droplets solidify on contact with the receiving surface.After each layer is deposited, the deposited material is planarized andcured with UV radiation prior to the deposition of the next layer.Optionally several layers can be deposited before planarization andcuring or multiple layers can be deposited and cured followed by one ormore layers being deposited and then planarized without curing.Planarization corrects the thickness of one or more layers prior tocuring the material by evening the dispensed material to remove excessmaterial and create a uniformly smooth exposed or flat up-facing surfaceon the support platform of the printer. Preferably planarization isaccomplished with a heated wiper device, such as a counter-rotatingroller. The process is continued until a useful finishedthree-dimensional design is prepared.

[0060] It should be noted that the consistency of the jetted buildmaterial of the present invention prior to curing must be sufficient toretain its shape and not be subject to viscous drag or shear from theplanarizer. This property is obtained by the solidification afterjetting of the about 5% to about 25% by weight wax that permeatesthroughout the still liquid urethane (meth)acrylate resin(s) and(meth)acrylate diluent(s) to form a supporting mesh or matrix for theliquid components. While the exact mechanism is not fully understood, itis theorized that the solidified wax support matrix increases theapparent viscosity of the jetted build material and provides sufficientsurface area to promote and facilitate the adhesion of the uncuredliquid components thereto to permit the jetted material to retain itsshape with a paste-like semi-solid consistency, resist theaforementioned viscous drag and shear stress during planarization, andnot be so large a percent of the composition to adversely affect thedesired physical properties of the cured build material.

[0061] The present invention is further described in detail by means ofthe following Examples and Comparisons. All parts and percentages are byweight and all temperatures are degrees Celsius unless explicitly statedotherwise.

EXAMPLES 1-5

[0062] Five UV curable phase change build material formulations weredeveloped having a viscosity of between about 13 to about 14 centipoise(cPs) at a temperature of about 80° C. The material formulations weretargeted to have a melting point of between about 50° C. to about 60°C., and a freeze point of between about 45° C. to about 55° C. It isdesired that the melting point of the material be at least lower thanthe dispensing temperature, but generally not lower than about 50° C. Amelting point of between about 50° C. and about 80° C. is acceptable,although preferably between about 50° C. and about 60° C. to assure thematerial remains in the flowable state in light of temperaturevariations that can occur in the print head. In the preferredembodiment, where a non-curable phase change support material isdispensed from the same print head as the curable phase change buildmaterial, the support material would have a similar melting point,freeze point, and viscosity at the dispensing temperature. Although nottested, the curable phase change build material formulations arebelieved to have a dispensing life of between about 3-5 weeks based onthe data from the thermal aging tests for similar formulations. Theformulations generally comprise between about 20% to about 40% by weightof high molecular weight reactive oligomers, between about 10% to about60% by weight of low molecular weight reactive (meth)acrylates, betweenabout 1% to about 6% by weight of a photoinitiator, and between about 5%to about 25% by weight wax. The reactive components of both high and lowmolecular weight materials comprise between about 75% to about 95% byweight of the composition. The combination of high and low molecularweight monomers and oligomers were accordingly adjusted so as to achievethe desired viscosity of between about 13 to about 14 centipoise for theformulation at a temperature of about 80° C. For the high molecularweight materials urethane acrylates were used alone or with epoxyacrylates. For the low molecular weight materials, methacrylates,dimethacrylates, triacrylates, and diacrylates were used in a variety ofcombinations. Non-reactive urethane waxes were used, althoughhydrocarbon waxes could also be used, such as carbon hydrogenated waxes,paraffin waxes, microcrystalline waxes, fatty ester waxes, and the like.However, the wax must be chosen such that it is relatively insoluble inthe monomer formulation upon cooling in order to form a solidplanarizable layer. MEHQ was present in small amounts (100 to 800 ppm)in each of the (meth)acrylate components when purchased from thesupplier. The components of these five exemplary build materialformulations are provided by weight percent in Table 1. TABLE 1 Mfg. IDGeneral Component No. Name Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 CN980 UrethaneAcrylate  7.2%  6.5%  7.2% CN981 Urethane Acrylate   26% E3200 EpoxyAcrylate   14%    6% CN975 Hexafunctional Urethane  7.2% Acrylate CN2901Urethane Acrylate 27.5%   27%  18.7% 27.5% SR203 Tetrahydrofurfuryl  18% Methacrylate SR205 Triethylene glycol   33% 46.5% 41.05%   15%dimethacrylate SR340 2-phenoxyethyl   19% methacrylate SR313 Laurylmethacrylate   18% SR454 Ethoxylated₃  4.5% TrimethylolpropaneTriacrylate SR604 Polypropylene glycol   12% monomethacrylate CD406Cyclohexane dimethanol   30% diacrylate SR493D Tridecyl methacrylate  19% ADS038 Urethane wax   7%  5.3%   10%   10%  9.3% ADS043 Urethanewax  4.3%   6%  1.5%    2%   2% I-184 Photo-initiator   2%   2%   2% 3.75%   2% TOTAL  100%  100%  100%   100%  100%

[0063] The following components used in the five formulations listed inTable 1 are available from the Sartomer Company, Inc. of Exton, Pa.under the following designations: CN 980, CN 981, CN 975, CN2901, SR203, SR 205, SR 340, SR 313, SR 454, CD 406, SR604, SR 493D. Thefollowing components used on the five formulations listed in Table I areavailable from American Dye Source, Inc. of Baie D'Urfe, Quebec, Canada:ADS 038, and ADS 043. The epoxy acrylate under the 10 designation E 3200is available as Ebecryl 3200 from UCB Chemical, Inc. of Atlanta, Ga. Thephotoinitiator under the designation 1-184 listed is available from CibaSpecialty Chemicals, Inc. of New York, N.Y.

[0064] The formulations in Table 1 were made in accordance with thepresent invention by mixing the individual components in a kettleequipped with a mixing blade. A kettle was preheated to about 85° C. andthe components placed into the kettle, the kettle closed and stirringwas commenced. Stirring continued as the components eventually equalizedto the temperature of the kettle. Stirring was then continued until ahomogenized molten state was achieved. The viscosity was measured andadjusted as needed. It took approximately 2.5 hours to mix a 75 poundquantity of the formulations to a homogenized state. The formulationswere then removed from the kettle and filtered through a 1 micronabsolute filter while in the flowable state. The formulations were thencooled to ambient temperature at which they transitioned from theflowable to the non-flowable state.

[0065] In a preferred embodiment, Selective Deposition Modeling (SDM)apparatus dispenses a preferred UV curable phase change material, suchas that in Example 4 of Table 1, to form the object and another non-UVcurable phase change material to form supports for the object, asneeded. This is desired so that the non-curable phase change materialcan be removed from the cured object by application of a solvent todissolve the support material or by application of heat to melt thesupport material.

[0066] A preferred support material formulation comprises from about 60%to about 80% by weight, more preferably from about 65% to about 75% byweight, and most preferably about 70% by weight octadecanol availablefrom Ruger Chemical of Irvington, N.J., and from about 20% to about 40%by weight, more preferably from about 25% to about 35% by weight, andmost preferably about 30% by weight of an abietic rosin ester tackifiersold under the designation of KE 100 available from Arakawa Chemical ofChicago, Ill. Octadecanol is a long chained aliphatic alcohol,hereinafter referred to as a fatty alcohol. Other suitable fattyalcohols can be used, as well as combinations of fatty alcohols, of thestructure C_(n)H_(2n+1)OH wherein n is an integer from about 12 to about22. These other fatty alcohols useful as support material, either aloneor in combination, may include dodecanol (C₁₂H₂₅OH), tetradecanol(C₁₄H₂₉OH), hexadecanol (C₁₆H₃₃OH), eicosanol (C₂₀H₄₁OH), and docosanol(C₂₂H₄₅OH). Additionally decanol (C₁₀H₂₁OH) may be useful incombinations with other fatty alcohols.

[0067] The support material formulation has a viscosity of between about10.0 to about 19.0 centipoise, more preferably between about 11.0 toabout 14.0, and most preferably between about 11.3 to about 11.8centipoise at a temperature of about 80° C., and a melting point ofbetween about 50° C. to about 65° C., more preferably from about 55° C.to about 62° C., most preferably from about 60° C. to about 62° C., anda freezing point of from about 45° C. to about 55° C., more preferablyfrom about 47° C. to about 52° C., and most preferably from about 49° C.to about 51° C.

[0068] The support material formulation was mixed in a kettle equippedwith a mixing blade. The kettle is preheated to about 85° C. and theoctadecanol is placed into the kettle by itself, as it has the lowermelting point, and the kettle is closed and stirring commenced. Once theoctadecanol has melted, the KE 100 is added to the mixture whilestirring continues. The kettle is closed and stirring continues until ahomogenized state of the mixture is achieved. The viscosity is measuredand adjusted if needed. The formulation is then removed from the kettleand filtered through a 1 micron absolute filter while in the flowablestate. The formulation is then cooled to ambient temperature wherein ittransitions from the flowable to the non-flowable state.

[0069] An alternate support material can employ hexadecanol in place ofthe octadecanol in the same weight percent in combination with theKE-100 tackifier. Hexadecanol is also a long-chained aliphatic alcoholwhich will also be referred as a fatty alcohol which creates a supportmaterial that melts between about 50° C. to about 52° C. and has afreezing point of about 39° C. to about 42° C. Hexadecanol is availablecommercially from Ruger Chemical of Irvington, N.J. Hexadecanol, as withthe other fatty alcohols, permits a support material to be formulatedwhich has a lower melting point and hence a lower temperature to beemployed to remove the jetted supports from the part.

[0070] In the preferred SDM apparatus of the present invention, the Z850print head is configured to also dispense a non-curable phase changesupport material as well as the curable phase change build material.Sample parts were made in this manner and the support material removedto expose the three-dimensional objects.

[0071] The support material is removed by further processing. Generally,thermal processing by the application of heat to bring the supportmaterial back to a flowable state is needed to remove substantially allof the support material from the three-dimensional object. This can beaccomplished in a variety of ways. For example, the part can be placedin an air heated chamber or in a heated vat of liquid material, such aswater or oil or heated support material or a combination of both heatedair and heated liquid material. Physical agitation may also be used,such as by directing a jet of the heated liquid material directly at thesupport material or moving the part with the attached support about inthe heated vat of liquid material. This can also be accomplished bysteam cleaning with appropriate equipment. Alternatively, the supportmaterial can also be removed by submersing the material in anappropriate liquid solvent to dissolve the support material.

[0072] After the support material was removed from the parts, thethree-dimensional objects were then tested to determine the resultingphysical properties achieved. The physical properties measured for thefive formulations are provided in Table 2 along with their viscosity's,melting points and freezing points. Only the formulation in Example 4was tested for mechanical impact strength properties after cure. TABLE 2Property Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Viscosity at 80° C.  12.9 cPs  12.9 cPs   12.9 cPs   12.8 cPs   13.1 cPs Melting point ° C. 52° C.  55° C. 57° C.   56° C. 53° C. Freezing point ° C. 46° C. 47.5° C. 50°C. 49.5° C. 45° C. Elongation % E 9% 4% 5% 11% 22.2% (after cure)Tensile Strength (psi)  2,340 psi  2,383 psi  5,597 psi  2,800 psi 2,771 psi (after cure) Tensile Modulus (psi) 92,000 psi 116,000 psi267,000 psi 108,500 psi 129,000 psi (after cure) Impact strength(ft- NotNot Not 0.24 Not lb/in) (Izod notched) Measured Measured MeasuredMeasured

[0073] The formulation of Example 4 was also measured or tested for thefollowing properties: Viscosity at 90° C. 10.2 cPs Viscosity at 75° C.14.5 cPs Viscosity at 70° C. 16.7 cPs Viscosity at 65° C. 19.4 cPsMelt/Freeze Temperature 58° C./49.5° C. Surface Tension @ 85° C.   35dyne/cm Jetting Temperature Density 0.99 grams/ml Uncured Density @ room1.01 grams/ml temperature

[0074] These mechanical properties (tensile strength and tensilemodulus) are far superior to those properties obtained in SDM usingthermoplastic phase change materials. For example, in U.S. Pat. No.6,132,665 to Bui et al., the non-curable thermoplastic phase changeformulation disclosed has an Elongation (% E) of 3 and a tensile stressof 435 psi (3 MPa). These physical properties are representative ofthose achieved using the ThermoJet® solid object printer dispensingThermoJet 2000 build material, both apparatus and material sold by 3DSystems, Inc. of Valencia, Calif. The five curable phase changeformulations clearly exhibit superior tensile strength (tensile strengthis a good property related to toughness—impact strength would be abetter measurement of improved properties, but the ThermoJet 2000material's impact strength is too low to measure) compared to thenon-curable thermoplastic formulations. For instance, the tensilestrength of the formulation in Example 1 is over 5 times greater thanthe tensile strength of the non-curable thermoplastic formulation.

[0075] While the invention has been described above with reference tospecific embodiments thereof, it is apparent that many changes,modifications, and variations can be made without departing from theinventive concept disclosed herein. For example, it should be noted thatit is possible to tailor the physical properties of the finalnon-curable phase change support material by use of a combination offatty alcohols, in conjunction with the abietic rosin ester.Accordingly, it is intended to embrace all such changes, modificationsand variations that fall within the spirit and broad scope of theappended claims. All patent applications, patents and other publicationscited herein are incorporated by reference in their entirety.

1-13. Cancelled.
 14. A method for creating raised area and specialprinting effects using ink jet technology comprising the steps of:depositing a UV light curable composition on an area selected for thespecial printing effects in an amount corresponding to the area selectedand a desired height for the raised area relative to a medium on whichit is deposited; depositing a non-curable support material on the areaselected wherein the amount of material to be deposited corresponds tothe area selected for said printing effects and the height of the raisedarea relative to the medium on which said composition is deposited;curing the area selected with UV light; and removing the supportmaterial by applying heat to melt away the support material.
 15. Amethod according to claim 14 wherein said step of depositing comprisesthe step of jetting the UV light curable composition and the non-curablesupport material.
 16. A method according to claim 15 wherein said stepof depositing comprises jetting the non-curable support material thatcomprises from about 50% to about 80% by weight of a fatty alcohol orcombinations of fatty alcohols of the structure C_(n)H_(2n+1)OH whereinn is an integer from about 12 to about
 22. 17. A method according toclaim 14 wherein the non-curable support material has a viscosity atabout 80° C. of from about 10.0 to about 19.0 centipoise.
 18. Aselective deposition modeling method of forming at least a portion of athree-dimensional object on a layer-by-layer basis comprising the stepsof: a) generating computer data corresponding to layers of said object;b) providing a UV curable build material which is a fluid at at leastone temperature between about 40° C. and about 90° C.; c) providing anon-curable support material which is a fluid at at least onetemperature between about 40° C. and about 90° C. comprising at leastone fatty alcohol of the structure C_(n)H_(2n+1)OH wherein n is aninteger from about 12 to about 22 and an abietic rosin ester; d)elevating the temperature of the build material and the support materialto a temperature above 70° C. to about 90° C.; e) selectively dispensingthe build material at the elevated temperature according to the computerdata to form a layer of the object; f) selectively dispensing thesupport material at the elevated temperature according to the computerdata to form a layer of support material contiguous to the buildmaterial; g) providing an environment that lowers the temperature of thedispensed build material and the support material into a solid state; h)subjecting the solid dispensed material to a UV light to cure the buildmaterial; and i) repeating steps e), f), g) and h) to form subsequentlayers until at least the portion of the object is formed.
 19. Themethod of claim 18 wherein step e) is accomplished by jetting thecomposition through at least one print head.
 20. The method of claim 19further comprising the non-curable support material comprising fromabout 60% to about 80% by weight of a fatty alcohol or combinations offatty alcohols of the structure C_(n)H_(2n+1)OH where n is an integerfrom about 10 to about 22 and the fatty alcohol comprises about 205 toabout 405 by weight of the non-curable support material.
 21. The methodof claim 20 wherein the non-curable support material has a viscosity atabout 80° C. of from about 10.0 to about 19.0 centipoise.
 22. The methodof claim 20 wherein the non-curable support material has a viscosity atabout 80° C. of from about 11.0 to about 14.0 centipoise.
 23. The methodof claim 20 wherein the non-curable support material has a viscosity atabout 80° C. of from about 11.3 to about 11.8 centipoise.
 24. The methodof claim 18 wherein step e) is accomplished by jetting the compositionthrough at least one piezoelectric print head.